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United States Patent |
5,061,237
|
Gessler
,   et al.
|
October 29, 1991
|
Method of purifying whole blood
Abstract
A medical device, particularly a filter, cannula, catheter, or implant made
of plastic or plastic-coated metal or glass for fixing disease-causing
microorganisms, particularly viruses, bacteria, and fungi as well as
pathogenic metabolic products, toxins, lipoid substances, and drugs,
wherein the plastic surface is provided (firmly attached thereto or
covalently bound therewith):
a) homologous or monoclonal immunoglobulins, preferably those that have
been afterpurified by affinity chromatography in the classes G1, G2, G3,
and/or G4 and/or IGM, IGE, IGD and/or IGA and/or the F(ab)2 fragments
thereof, preferably those that have been afterpurified by affinity
chromatography, which are selectively active against the specific antigens
or antigenic determinants of the respective disease-causing
microorganisms, particularly viruses, bacteria, and fungi as well as
pathogenic metabolic products, toxins, lipoid substances (e.g., lipids),
and drugs, or
b) gamma globulins, particularly heterologous gamma globulins, which are
active against the most widely differing antigens or antigenic
determinants of the disease-causing microorganisms concerned, particularly
viruses, bacteria, and fungi.
Inventors:
|
Gessler; Reiner (Aschaffenburg, DE);
Rycyk; Manfred (Koerle, DE)
|
Assignee:
|
Cytomed Medizintechnik GmbH (Aschaffenburg, DE)
|
Appl. No.:
|
420770 |
Filed:
|
October 11, 1989 |
Foreign Application Priority Data
| Jul 02, 1985[DE] | 3523615 |
| Jul 02, 1985[DE] | 3523616 |
Current U.S. Class: |
604/5.02; 436/512; 604/5.03; 604/5.04 |
Intern'l Class: |
A61M 037/00 |
Field of Search: |
604/4-6,264-265
436/512,528,531
|
References Cited
U.S. Patent Documents
4272504 | Jun., 1981 | Kim et al. | 436/825.
|
4279885 | Jul., 1981 | Reese et al. | 436/518.
|
4292403 | Sep., 1981 | Duermeyer | 435/5.
|
4374925 | Feb., 1983 | Litman et al. | 435/7.
|
4425438 | Jan., 1984 | Bauman et al. | 436/824.
|
4478946 | Oct., 1984 | Van der Merve et al. | 436/518.
|
4552839 | Nov., 1985 | Gould et al. | 436/824.
|
4624930 | Nov., 1986 | Tanswell et al. | 436/824.
|
4632901 | Dec., 1986 | Valkirs et al. | 436/824.
|
4634417 | Jan., 1987 | Korec | 604/6.
|
4664913 | May., 1987 | Mielke et al. | 604/6.
|
Foreign Patent Documents |
0082345 | Jun., 1983 | EP | 604/5.
|
0109531 | May., 1984 | EP | 604/5.
|
0138297 | Jun., 1984 | EP.
| |
0132534 | Feb., 1985 | EP | 604/4.
|
0151357 | Nov., 1981 | JP | 436/518.
|
0170263 | Oct., 1982 | JP | 128/1.
|
0058947 | Dec., 1982 | JP | 128/1.
|
0139936 | Aug., 1984 | JP | 604/4.
|
Other References
Introduction to Immunology, John W. Kimball, Macmillan Publishing Co.,
Inc., New York; 1983, pp. 233-234, 246.
|
Primary Examiner: Rosenbaum; C. Fred
Assistant Examiner: Maglione; Corrine
Attorney, Agent or Firm: Armstrong, Nikaido, Marmelstein, Kubovcik & Murray
Parent Case Text
This application is a continuation of application Ser. No. 220,880 filed
June 22, 1988, now abandoned, which is a continuation of application Ser.
No. 881,416 filed July 2, 1986 now abandoned.
Claims
We claim:
1. A method for purifying whole blood which comprises contacting whole
blood containing a pathogenic microorganism or a metabolic product of a
pathogenic microorganism with a plastic surface having attached thereto
F(ab).sub.2 fragments from a homologous or monoclonal immunoglobulin
selectively active against a specific antigen or antigenic determinant of
the pathogenic microorganism or the metabolic product of the pathogenic
microorganism, wherein the F(ab).sub.2 fragments are free of Fc fragments,
to separate the pathogenic microorganism or the metabolic product of the
pathogenic microorganism from the whole blood contacted with said plastic
surface.
2. A method according to claim 1, wherein the F(ab).sub.2 fragments are
covalently bound to the plastic surface.
3. A method according to claim 1, wherein the F(ab).sub.2 fragments were
obtained by enzymatically cleaving the immunoglobulin to form F(ab).sub.2
and Fc fragments and wherein the Fc fragments were separated before the
F(ab).sub.2 fragments were attached to the plastic surface.
4. A method according to claim 1, wherein the immunoglobulin is at least
one of G1, G2, G3, G4, IGM, IGE, IGD or IGA immunoglobulin.
5. A method for purifying whole blood which comprises:
a) withdrawing whole blood containing a pathogenic microorganism or a
metabolic product of a microorganism from a body,
b) contacting the whole blood removed from the body with a plastic surface
having attached thereto F(ab).sub.2 fragments, from which the Fc fragments
have been separated, of a homologous or monoclonal immunoglobulin
selectively active against a specific antigen or antigenic determinant of
the pathogenic microorganism or the metabolic product of the
microorganism, and
c) returning the thus contacted whole blood to the body.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a medical device, more particularly a filter, a
cannula, a catheter or an implant, of plastic or plastic-coated metal or
glass, which can be used inside or outside the human body to fix, and
thereby to render harmless, disease-causing microorganisms, particularly
viruses, bacteria, and fungi, as well as pathogenic metabolic products,
toxins, lipoid substances, and drugs. The invention relates in particular
to filters for the separation of disease-causing microorganisms,
especially viruses, bacteria, and fungi, as well as pathogenic metabolic
products, lipoid substances, toxins, and drugs from blood, as well as
cannulas, catheters, and implants that can be introduced into the human
body without the risk of infection.
2. Description of the Prior Art
Unexamined West German Patent Application DE-OS 32 28 849 discloses a
medical device to be introduced into the body and having a coating which
releases microbicidal metal ions. The metal ions are gold, silver, and
copper ions.
With devices to be introduced into the human body, e.g., probes, it is also
well known in the art to treat the surface of the probes with iodine
compounds to reduce the risk of infection.
However, the prior art processes have proved to be inadequate in practice,
because the applied agents such as precious metal ions, iodine compounds,
or antibiotics are released from the coated material and thus the risk of
infection is reduced only during a brief period. Also, any microorganisms
that may be present react metabolically with the released substances, so
that resistances and the like may be developed. In addition to the risk of
infection, the formation of a fibrin layer on the surface of intravasal
catheter has a deleterious effect on catheters to be introduced into the
body. The proposed solution, i.e., to coat intravasal catheters with
heparin in order to avoid the usual fibrin deposits, has likewise proved
unsuccessful.
The increasing development of multiple resistance and the high financial
cost associated therewith call for a new protective system. Therefore,
catheters, cannulas, or implants that can remain in the body for long
periods of time without the risk of infection are desired.
Furthermore, efforts have been made for a long time in the medical field to
develop treatment methods for highly toxic, viral or bacterial infectious
diseases, such as AIDS, hepatitis A, hepatitis B, non-A, non-B hepatitis,
tetanus, and genetically conditioned metabolic disorders, e.g.,
phenylketonuria, or other intoxications such as, for example, with
digitalis glycosides or barbiturates. Success, however, has been very
limited. Interferon has been used as an established agent against viral
diseases, but the efficacy of interferon treatment is very limited,
because the spectra of the various interferons and the organ specificities
thereof differ considerably.
Despite substantial outlays of material and work involved, the therapeutic
results to date have also been limited with respect to bacterial diseases,
such as tetanus, genetically conditioned metabolic disorders such as
phenylketonuria, or intoxications, e.g. with digitalis glycosides or
barbiturates.
Accordingly, a simple method was desired by which the disease-causing
viruses, bacteria, fungi, pathogenic metabolic products, lipoid substances
(particularly lipids), and drugs can be removed from, or filtered out, of
the blood. However, the treatment method is to be designed such that the
disease-causing substances or other substances, if they can be removed by
filtration, do not remain in the blood as an antigen-antibody complex.
Accordingly, the invention has as its object the development of a medical
device, particularly cannulas, catheters, and implants as well as filters
made of plastic or plastic-coated metal or glass, by means of which
disease-causing microorganisms, particularly viruses, bacteria, and fungi
as well as pathogenic metabolic products, toxins, lipoid substances
(especially lipids), and drugs in blood, particularly human blood, can be
fixed inside or outside the human body in such a way that the infections
caused thereby can be prevented with assurance, or that these undesirable
substances can be reliably removed from the blood without risk.
SUMMARY OF THE INVENTION
It has now been found that this object can be achieved with a medical
device, particularly a filter, cannula, catheter, or implant made of
plastic or plastic-coated metal or glass for fixing disease-causing
microorganisms, particularly viruses, bacteria, and fungi as well as
pathogenic metabolic products, toxins, lipoid substances, and drugs, said
device being characterized by the fact that the plastic surface is
provided with (firmly attached thereto or covalently bound therewith):
a) homologous or monoclonal immunoglobulins, preferably those that have
been afterpurified by affinity chromatography in the classes G1, G2, G3,
and/or G4 and/or IGM, IGE, IGD and/or IGA and/or the F(ab)2 fragments
thereof, preferably those that have been afterpurified by affinity
chromatography, and which are selectively active against the specific
antigens or antigenic determinants of the disease-causing microorganisms
concerned, particularly viruses, bacteria, and fungi as well as pathogenic
metabolic products, toxins, lipoid substances (e.g., lipids), and drugs,
or
b) gamma globulins, particularly heterologous gamma globulins, which are
active against the most widely differing antigens or antigenic
determinants of the disease-causing microorganisms concerned, particularly
viruses, bacteria, and fungi.
Used as plastic materials in medical technology are common plastics, for
example, polyolefins, polyesters, polyethers, polyamides, polyimides,
polyurethanes, polyvinyl chlorides, polysulfones, polystyrenes,
polyacrylates, polymethacrylates, polypropylenes, polyvinylpyrrolidones,
fluoropolymers, plastics based on acrolein, derivatives of said compounds,
mixtures, and copolymers thereof, as well as silicone rubber. Polystyrene-
and polyurethane-based plastics are particularly suitable. Also suitable
for this purpose is glass that has been pretreated, for example, with
acrolein, such as Controlpore glass (a product of Sigma), and the like.
The surface of the plastic employed in accordance with the teachings of
the invention is preferably pretreated with gamma rays or ozone, because
the adhesive strength of the applied immunoglobulins or gamma globulins is
increased thereby. Pretreatment of the plastic surface or glass surface by
ion etching or by acrolein or an acid is another option. Particularly
advantageous is the application of a coupling agent or spacer to the
plastic surface to improve the adhesive strength of immunoglobulines or
gamma globulins to the plastic surface, particularly those from the group
of cyanogen bromide, thiophosgene, and thionyl chloride, which can also be
used to activate the plastic surface and can also produce a covalent bond
between substrate and globulin.
Spacers are molecular connectors for increasing the distance between the
surface of the carrier material and the immunoglobulin. One skilled in the
art is familiar with the term spacer. The covalent bond is effected, for
example, with cyanogen bromide or thiophosgene.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described in greater detail with reference to two
preferred embodiments, but is not limited thereto, namely a filter for the
separation of disease-causing microorganisms, particularly viruses,
bacteria, and fungi as well as pathogenic metabolic products, lipoid
substances (e.g., lipids), and drugs from blood, on the one hand, and
catheters, cannulas, or implants which can remain within the body for a
long time without risk of infection, on the other.
A filter of the type indicated in the introduction has now been developed,
which is characterized by the fact that it is made of a plastic which can
be perfused by blood and is physiologically safe, whereby the plastic
surface of the filter is provided with homologous or monoclonal
immunoglobulines, preferably those that have been afterpurified by
affinity chromatography in the classes G1, G2, G3 and/or G4, and/or IGM,
IGE, IGD and/or IGA and are selectively active against the specific
antigens or antigenic determinants of the particular viruses, bacteria,
fungi, pathogenic metabolic products, toxins, lipoid substances, or drugs.
The immunoglobulins are applied securely to the surface of the filter by
adsorption or by means of a coupling agent or covalent bond.
Preferably, the plastic surface of the filter is one that has been
pretreated with gamma rays or ozone, because this increases the adhesive
strength of the immunoglobulins applied by means of an impregnation
process. Adherence of immunoglobulins of classes G1, G2, G3 and/or G4
and/or IGM, IGE, IGD and/or IGA to the plastic surface of the filter can
be enhanced further by applying, after surface treatment with gamma rays
or with ozone, a coupling agent or acrolein to the surface to improve the
adherence of the immunoglobulins to the plastic surface, especially by the
formation of a covalent bond.
The filter may be a compact filter, membrane filter, packed filter,
molecular sieve filter, or capillary filter. Particularly suitable is also
an enclosure filled with spherical, annular, saddle-shaped, spiral,
stellate, cylindrical or reticulate plastic particles. The capillary blood
filters of known construction can also be used for the purposes of the
invention.
The separation of disease-causing substances or other substances from the
blood is effected in a manner such that blood from the body is pressed
into the filter by means of a blood pump, during which the filtration rate
is approximately 6 to 30 ml of blood per minute. The total blood volume of
the patient with, for example, AIDS, hepatitis A, hepatitis B, non-A,
non-B hepatitis, viral encephalitis, or some other highly pathogenic
treatment-resistant bacterial or mycotic infection or a genetically
conditioned, virus-induced, or genetic metabolic disorder such as
phenylketonuria or an intoxication, is passed across the filter of the
invention as in hemodialysis.
The antigen-antibody complex formation specific in each case is effected by
means of the homologous or monoclonal immunoglobulins applied to the
plastic surface of the filter incorporating the invention, i.e., the
particular viruses, bacteria, pathogenic metabolic products, toxins,
lipoid substances, or drugs are filtered out of the blood flowing through
the filter by binding to the antibodies.
The abovementioned pathogenic or other pathogenic substances or organisms
are immobilized in this manner on the filter. Thus, the antigen-antibody
complex is not removed from the blood stream.
The reaction surface, i.e., the size of the filter surface coated with
antibodies, is determined on the basis of the filter concerned. The blood
purified in this manner is subsequently retransfused.
Blood washing* is carried out at about 37 degrees Celsius and is repeated
two to three times for disease-causing bacteria and fungi and five to six
times for the separation of disease-causing viruses, until the pathogens
are totally removed from the blood. For the removal of viruses, the blood
washing must be repeated after cell lysis, i.e., the particular cycle of
lysis which manifests itself in a corresponding rise in temperature is
used as an indication for the next blood washing. The repeated use of
blood washing in the case of viruses bound to DNA is necessary, because
these viruses react with the antibodies on the surface of the filter only
after the corresponding cell lysis.
* Blutwaesche: According to Bunjes, this word means "lavage of the blood,
systemic lavage, hematocatharsis, washing-out of the blood by means of the
artificial kidney." However, according to our medical consultants,
"Blutwaesche" as applied to this invention is none of these, nor is it
"hemodialysis", which is described in our German medical dictionaries as
"The removal of certain elements from the blood by virtue of the
difference in the rates of their diffusion through a semipermeable
membrane". We decided to translate it literally as "blood washing", which
makes sense, according to our consultants, since it is related to the AIDS
problem.
In highly pathogenic, treatment-resistant microorganisms and in
intoxications not associated with DNA, one or two passages of the infected
blood through the novel filter are generally sufficient. In genetically
conditioned metabolic disorders, blood washing is to be repeated in
accordance with the resulting concentration of the pathogenic metabolic
products.
The immunoglobulins G1, G2, G3 and/or G4 and/or IGM, IGE, IGD and/or IGA
are applied to the plastic surface of the filter in the appropriate
immunoglobulin solution. The impregnation times are approximately 1 to 10
hours. The filter occupied by the immunoglobulins is then washed with a
phosphate buffer solution to wash away excess immunoglobulines, after
which the filter is dried.
As an alternative to the abovementioned impregnation process, these
immunoglobulins can be applied over activated plastics via cyanogen
bromide, thiophosgene, or thionyl chloride following gamma irradiation by
means of coupling agents or a similar process producing covalent bonds.
In the past, blood washing has been effected by reacting full antibodies
with the particular antigens of the substances to be removed to form an
antigen-antibody complex. Optimization of this process is particularly
achieved when treating infectious diseases, such as AIDS, by pretreating
in the immunoglobulins with pepsin, which results in the cleavage of the
F(ab)2 and Fc fragment. The Fc fragment is then separated by
chromatography. Sepharose CL6B is used for this purpose. In so doing, the
activated gel is left to react for a period of 40-54 hours at 2-10 degrees
Celsius, resulting in the quantitative separation of the Fc fragment. The
F(ab)2 fragments thus obtained are now reacted with the plastic surfaces.
Glass beads are used as carriers in addition to polar plastics.
The significance of blood washing by means of the separated immunoglobulins
F(ab)2 is based on the following:
1. When whole blood reacts with immunoglobulin that has not been separated,
several nonspecific bindings to the Fc fragment occur in addition to the
specific antigen binding to the F(ab)2 fragment, where the complement
factors inter alia represent an important group in this case. In terms of
practical application, this means that substances important for the body's
own resistance to infections are removed from the already weakened
patient. Phagocytosis of the microorganisms concerned is appreciably
reduced.
The problems of any thrombus formation when carrying out the blood washing
described herein is precluded by the fact that 5-25% of the coated
reaction surface is occupied not by the F(ab)2 fragment, but by heparin.
In contrast to F(ab)2 molecules, which are covalently bound, heparin is
applied by adsorption. The filtration unit employed for the blood washing
is to be sterilized very carefully with ethylene oxide or by gamma
irradiation because of the protein characteristics of the active
antibodies, and it cannot be guaranteed that inactivation of the active
antibodies will not occur.
The following new sterilization procedure is an option for the absolute
avoidance of inactivation:
A mixture of heterologous immunoglobulins is placed in a physiologic
solution (e.g., Ringer's solution). The filtration unit is charged with
this solution and left for a period of 10-30 minutes. Because of the
heterologous immunoglobulins, an antigen-antibody reaction of different
avidity occurs with microorganisms or pyrogens that may be present. The
size of the antigen-antibody complex requires that the thusly bound
microorganism or pyrogen be washed out in three subsequent washes with a
physiologic solution without antibodies.
Medical cannulas, catheters or implants embodying the invention are
characterized by adsorption of gamma globulins, particularly heterologous
gamma globulins, on the plastic surface.
Thus, the basic consideration is concerned with the fact that all
microorganisms, whether bacteria or viruses, have a number of antigenic
determinants at their disposal. Within the body, these cause the
production of specific antibodies, which form the antigen-antibody complex
necessary for recovery. The microorganisms are immobilized solely by the
formation of the antigen-antibody complex on the plastic surface. This
prevents the microorganisms from gaining further ground in the body. The
antigen-antibody complex formation on the surface of the plastic can be
achieved in vivo with an appropriate coating of implants, catheters,
cannulas, and probe materials, as well as artificial organs, with gamma
globulins. This means that microorganisms are bound by contact with the
gamma globulins due to their antigenic properties , thereby inhibiting
their movement. Thus, further penetration or multiplication in the body is
precluded.
Since the antibodies or gamma globulins are firmly, preferably covalently,
bound to the plastic surface and are not released to the medium, no
metabolic transformation will occur, because the effect described above is
an immobilizing, rather than a bactericidal or bacteriostatic, effect.
The all-around coating of the catheters, cannulas, and implants described
herein also inhibits retrograde microbial migration on the outer and inner
wall of the these articles.
Preferably, the plastic surface or plastic material consists of
polypropylene, polyurethane, polyvinylpyrrolidone, polyacrylate,
polymethacrylate, polyamide, or copolymers thereof.
The plastic surface is treated prior to the application of the gamma
globulins by means of gamma rays, ion etching, ozone etching, or with a
solution with a pH of 7.5 to 10.5 or with acrolein, in order to improve
the adhesive strength of gamma globulins to the surface. Depending on the
plastic starting material, the treatment is carried out at a pH of 7.5 to
10.5, the reaction time being 5 to 10 minutes likewise depending on the
plastic. The plastic surface to be coated can also be roughened,
particularly by alkylation treatment with methyl iodide.
In addition to the roughening of the surface, the plastic can also be
treated with a coupling agent, particularly cyanogen bromide,
thiophosgene, or thionyl chloride, which also causes the gamma globulins
to adhere to the plastic surface, especially via the formation of a
covalent bond.
Another option for application to the plastic surface of cannulas,
catheters, implants, probes, vascular prostheses, and cardiac pacemakers
is the impregnation of the plastic surface pretreated with an appropriate
roughening operation, with the saturated gamma globulin solution. The
impregnation of the plastic surface is carried out at approximately
20.degree. to 40.degree. C., and for a period of about 1 to 10 hours.
After the binding by means of a coupling agent or after the adsorption of
the gamma globulins on the plastic surface, the carrier materials are
rinsed with a phosphate buffer solution to wash out excess gamma
globulins. The materials are then dried at an appropriate temperature
(20.degree. to 40.degree. C. for 8 to 24 hours) and sterilely packed.
Only polar plastics with the necessary physical properties, such as
elasticity and fracture toughness, are used as plastic materials for
introduction into the body.
A major aspect of the novel medical cannulas, catheters, or implants is the
use of preferably heterologous gamma globulins, because only coating with
this type of gamma globulins ensures the possibility of binding all the
microorganisms.
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